Conversion of a normally gaseous olefin other than ethylene to isobutane



W. J. MATTOX CONVERSION 0F A NORMALLY GASEOUS OLEFIN June 24, 1947. 2,422,692

` OTHER THAN ETHYLENE To IsoBUTANE FiledA Oct. 29, 1943 AUNLNQ NN WANNA.

Patented June 24, 1947 CONVERSION OF A NORMALLY GASEOUS OLEFIN OTHER THAN ETHYLENE TO ISO- BUTAN E William J.' Mattox, Riverside, Ill., assignor to Universal Oil Products Company, Chicago, Ill., a corporation of Delaware appuwtnm -october 29, 1943, serial No. 508,236

(ci. 26o-67.6)

` 7 Claims.

This invention relates to the conversion of normallygaseous oleilns into higher boiling, more valuable hydrocarbons. A

The invention is particularly applicable to the treatment of normally gaseous hydrocarbons recovered from, cracking plants, although it is understood that normally gaseous olefins from other sources may abe utilized.

In a. broad aspect the present invention relates to the conversion of a normally gaseous oleiln fraction comprising ethylene and propylene and/or butylene into isobutane and normally liquid hydrocarbons, which comprises subjecting said normally gaseous olefin fraction to conversion in the presence of a polymerizlng catalyst and a relatively inactive non-olefinic liquid hydrocarbon diluent under conditions` to convert the propylene and/or butylene into isobutane and higher boiling hydrocarbons while leaving the ethylene substantially unconverted.

In one specific embodiment the present invention comprises a process for the production of normally liquid hydrocarbons from a normally gaseous olefin fraction comprising ethylene and propylene and/or butylene by subjecting the normally gaseous olefin fraction to conversion in the presence of a polymerlzing catalyst at a temperature of from about 200 to about 500 C., a superatmospheric pressure of from about 100 to. about 1000 pounds per square inch, or more, and at a weight hourly space velocity of from about 0.5 to about 20, or more, to thereby form isobutane and normally liquid hydrocarbon-s from the propylene and/or butylene while leaving the ethylene substantially unconverted, separating an iscbutane- 1 containing fraction and an ethylene-containing fraction from the products of said conversion, and subjecting the isobutane to' alkylation with the ethylene in the presence of an alkylation catalyst.

In still another embodiment of this invention the normally 'liquid hydrocarbons used or produced in the olefin conversion step of the process may be subjected, all or in part, to cracking in order to produce normally gaseous oleflns. 'I'he normally gaseous olefins so produced are then supplied to the olefin conversion step for further conversion in the process.

According tothe present invention propylene and/crbutylene are converted in the presence of ethylene and selected, polymerization catalysts to produce isobutane and normally liquid hydrocarbons without substantial conversion of ethylene.

The conversion is effected in the presence of a ,polymers produced in the heretofore proposed polymerization processes.

The relatively inactive non-olefinic liquid hydrocarbon may suitably comprise aromatic hydrocarbons, alkyl aromatic hydrocarbons, parainic hydrocarbons, naphthenic hydrocarbons or a mixture thereof. As one of the essential features of the present invention it has been found that the Weight ratio of non-olenic hydrocarbon to normally gaseous olefin converted should not be less thanabout 1:1.

The selected catalysts which have been found suitable for this reaction include the so-called solid phosphoric acid" catalyst which comprises a composite of phosphoric acid and kieselguhr or other suitable carriers, and composites of silica and alumina. In addition to silica. and/or alumina, other suitable oxides such as thoria, titania, zirconia, etc., or various combinations of these oxides may be employed.

The olen. conversion process is effected at a temperature within the range of from about .200 to about 500 C. and 'preferably of from about 300 to about 400 C., at a. superatmospheric pressure of from about 100 to about 1000 pounds or more and preferably of from about 300 to about 800 pounds, while employing a weight hourly space velocity of from about 0.5 to about 20 or more and preferably within the range of from about 1 to about l0. .By weight hourly space velocity it is meant the weight of total hydrocarbons per hour per weight of catalyst in the reaction zone. It is understood thatv the temperature, pressure and space velocity will be correlated to produce the desired result.

The invention will be further explained in connection with the accompanying diagrammatic intention of unduly limiting the same.

Referring to the drawing, a normally gaseous olefin fraction containing ethylene and propylene and/or butylene is introduced to the process through line I and is supplied to olen conversion zone 3. As heretofore mentioned, this normally gaseous fraction may'suitablyl comprise a gas fraction recovered from either a thermal or catalytic cracking operation. These normally gaseous fractions as usually recovered contain olens and paraflinic hydrocarbons and it is a particular feature of the present invention that the presence Aof normally gaseous paralnic hydrocarbons will not unduly affect the olen conversion step or the process. It is understood that normally gaseous olens obtained from other wherein the reactants are intimately contactedV with the catalyst. One suitable method comprises disposing the catalyst as a xed bed within a reaction zone and passing the reactants and diluent upwardly or preferably downwardly through thecatalyst. Other suitable methods of operation such as the so-called fluidized bed or slurry type of operation may in some cases be satisfactorily employed.

' The normally liquid hydrocarbon diluent serves not only to produce the desired conversion of the olefins, but also to prolong the life of the catalyst. The proper state of hydration of the catalyst, which is essential with some composites can be maintained by the introduction of regulated quantities of water as such oras alcohol or other oxygenated compounds which yield water under the conditions of operation. This is not illustrated in the drawing but may readily be accomplished by well known means.

The products from zone 3 are directed through line 4 to separation zone 5 which may comprise one or a plurality of `suitable fractionating, distilling, absorbing and/or stripping zones in order to separate the products into the desired fractions. This separation also includes the separation of the hydrocarbons which were originally present in the charging stock introduced to line I and which were unconverted in zone 3. Normally gaseous hydrocarbons boiling -below ethylene may be withdrawn from the upper portion of zone 5 through line 6 and may be removed from the process.

An ethylene-containing fraction may be withdrawn from zone `5 through line 1 and may be removed from the process, but preferably all or a portion thereof is directed through line 8 for subsequent conversion in the manner to be hereinafter set forth. A propylene-containing fraction, which may or may not contain propane may be withdrawn from zone 5 through line 8' and may be removed from the process or, if desired,

all or a portion of this fraction may be recycled, either with or without intervening treatment to separate the propylene from the propane, by way of lines 9 and I to zone 3 for further conversion therein.

An isobutane-containing fraction may be withdrawn from zone 5 through line I0 and may be removed from the process, but preferably all or a portion thereof is directed by way of line II for subsequent conversion in the manner to be hereinafter set forth. When desired, hydrocarbons boiling within the range of gasoline or any fraction thereof, such as 2,3-dimethylbutene and/or 2,3-dimethylbutane, may be withdrawn from zone 5 through line I2 and may be recovered for any desired use, including blending with the normally liquid nal products f the process if desired. Higher boiling liquid products may be withdrawn from zone through line I3 and may be removed from the process or, if desired, may be directed through line` Il for further conversion in a manner to be hereinafter described in detail. It is also Within the scope of the invention to omit line I2 and withdraw all of the normally.. liquid products .from zone 5 through line I3.

In accordance with the invention as hereinbefore set forth, the final products of the process may comprise ethylene, isobutane and normally liquid hydrocarbons. The hereinafter described specific embodiment of the invention is particularly desirable in view of the large demands for normally liquid hydrocarbons of branched chain structure including such compounds as 2,3-dimethylbutane. In accordance with this embodiment of the invention the isobutane recovered through line II and the ethylene recovered through line 8 are subjected to alkylation in order to produce 2,3-dimethylbutane and other normally liquid branched chain hydrocarbons.

This embodiment of the invention may be accomplished by introducing the isobutane through line II and the ethylene through line 8 into alkylation zone I5, which zone may comprise any suitable system for effecting the desired alkylation. Suitable catalysts include the metal halides of the Friedel-Crafts type and particularly aluminum chloride which is used in conjunction with hydrogen chloride and which is normally employed at a temperature of from about 0 to about C. and under sufficient pressure to maintain the reactants in substantially liquid phase. Other suitable catalysts include a. mixture of boron fluoride and hydrogen fluoride.

Alkylation zone I5 as illustrated is intended to include suitable separation means whereby light material may be withdrawn from the process or all or a portion thereof and particularly unconverted reactants and/or hydrogen halide may be recycled by way of lines I'I and 8 to zone I5. Likewise, higher boiling material may .be withdrawn from zone I5 through line Is and may be removed from the process or, if desired, all or a portion thereof and particularly the catalyst,

when the latter is used in the form of a sludge,

may be recycled by way of lines I9 and 8 to zone I5. It is understood that any suitable concentration or other purification treatment may be employed to separate these materials prior to recycling.

The desired alkylation product, which will contain 2,3-dimethylbutane, may be withdrawn from zone I5 through line 20 and may be recovered as the primary nal product of the process in this embodiment of the invention. As heretofore set forth, the alkylation product withdrawn through line 20 may be blended, al1 or in part, with the normally liquid hydrocarbons withdrawn through line I2 from zone 5.

In still another embodiment of the invention,

the normally liquid hydrocarbons withdrawn through line I3 from zone 5 may be directed through line I4 into cracking zone 2|. Cracking zone 2| may comprise any suitable system, which may be either catalytic or non-catalytic, in order to convert the normally liquid hydrocarbons into normally gaseous hydrocarbons. Zone ZI likewise includes suitable separation means so that light gases boiling below ethylene may be withdrawn from zone 2I through line 22 and may be removed from the process. Ethylene, propylene and butylene, together with their corresponding paraffinic hydrocarbons'if any, may be withdrawn through line 23 and may be removed from y. hydrogen chloride at 5 the process, but .preferably at least a portion thereof is directed by way of lines 24 and I to zone 3 for further conversion in the manner hereinbefore set f orth. Hydrocarbons boiling within the range of gasoline or any particular fraction thereof may be withdrawn from zone 2| through line 25 and may be removed from the process. When desired, all or a portion of this fraction may be blended with the nal products withdrawn through lines l2 and 20 as heretofore set forth. Higher boiling liquid hydrocarbons may be Withdrawn from zone 2| through line 26 and may be removed from the process or all or a portion thereof may be recycled by way of' lines 21 and I4 to zoneZl for further conversion therein. When desired, line 25 may be omitted and the total normally liquid hydrocarbons from zone 2l may be withdrawn through line 26.

The following example is introduced for the purpose of further illustrating the novelty and utility of the present invention but not with the intention of unduly limiting the same.

A normally gaseous fraction recovered as an overhead stream from a cracking plant absorber contained 5.3 volume per cent of ethylene and 12 volume per cent of propylene, the other products comprising hydrogen, methane, ethane, propane and a minor. amount of C4 and heavier hydrocar-A bons.

The gaseous fraction mentioned above may be subjected to contact with a solid phosphoric acid catalyst at a temperature of about 300 C., a, superatmospheric pressure, of about .500 pounds and an hourly weight space velocity of about 4 in the presence of a kerosene fraction. The

weight ratio of kerosene to propylene may be then supplied to the olefin conversion zone for l further treatment therein.

I claim as my invention:

1. A process for producing isobutane from a hydrocarbon fraction containing ethylene and a higher molecular weight normally gaseous olefin, which comprises subjecting said fraction to the action of a. solid polymerizing catalyst comprising silica and an oxygen-containing compound selected from the group consisting of phosphoric acid, alumina, thoria, titania, and zirconia, in the presence of a non-oleiinic liquid hydrocarbon diluent at a temperature of from about 200 C. to about 500 C., a weight hourly space velocity of V from about 0.5 to about 20, and a pressure of from about to about 1000 pounds per square inch while Amaintaining the weight ratio of non-olenic liquid hydrocarbon to said normally gaseous olen at not less than 1: 1.

2. The process of claim 1 further characterized in that said catalyst comprises a solid phosphoric acid polymerizing catalyst.

3. The process of claim 1 furthe; characterized in that said catalyst comprises a composite of phosphoric acid and kieselguhr.

4. The process of claim 1 further characterized in that said catalyst comprises a composite of silica and alumina.

5. The process of claim 1 further characterized in that said diluent comprises a, kerosene fraction.

6. 'I'he process of claim 1 further characterized in that said hydrocarbon fraction comprises ethylene and propylene.

7. The process of claim 1 further characterized in that said hydrocarbon fraction comprises ethylene and butylene.

WILLIAM J. MATIOX.

REFERENCES CITED The following references are of record inthe l Number Name Date 2,158,559 Atwell May. 16, 1939 2,198,937 Frey 1 Apr, 30, 1940 2,102,073 Ipatieff Dec. 14, 1937 2,243,298 Thomas May 2'7, 1941 2,165,372 Haag July 11, 1939 2,211,747 Goldsby Aug. 13, 1940 2,298,330 Angell Oct. 13, 1942 2,340,600 Lamb Feb. 1, 1944 '2,349,160 Frey May 16, 1944 2,282,602 Drennan May 12, 1942 2,362,311 Rubin s Nov. '1, 1944 2,356,374 Blount Aug, 22, 1944 2,385,344 Burk Oct. 29, 1943 2,285,920 Gage June 9, 1942 OTHER RFRENCES Ipati'ei, "Catalytic Refining Methods Oil and Gas Jour.; Mar. 30, v,1939; pages 86, 88, 91, and 93. 260-676.

Ipatie', Catalytic Reactions-Temperatures;

. Macmillan; 1936; pages 607-623.;T (Copy in Div. 

